Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0012872 (DNA marker)
 929 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Screening purpose-built libraries with minisatellite probes, we have isolated 36 bovine variable number of tandem repeat markers (VNTRs) characterized by a mean heterozygosity of 59.3 within the American Holstein breed. Matching probabilities and exclusion powers were estimated by Monte-Carlo simulation, showing that the top 5 to 10 markers could be used as a very efficient DNA-based system for individual identification and paternity diagnosis. The isolated VNTR systems should contribute significantly to the establishment of a bovine primary DNA marker map. Linkage analysis, use of somatic cell hybrids, and in situ hybridization demonstrate that these bovine VNTRs are scattered throughout the bovine genome, without evidence for proterminal confinement as in the human, and that at least some of them are organized as clusters. Moreover, Southern blot analysis and in situ hybridization demonstrate conservation of sequence and map location of minisatellites within Bovidae.
 ...
PMID:Characterization of a set of variable number of tandem repeat markers conserved in bovidae. 176 84

To assess the association between recombination and nondisjunction of chromosome 21, we analyzed cytogenetic and DNA markers in 104 trisomy 21 individuals and their parents. Our DNA marker studies of parental origin were informative in 100 cases, with the overwhelming majority (94) being maternal in origin. This value is significantly higher than the 75%-80% maternal nondisjunction rate typically observed in cytogenetic studies of trisomy 21 and illustrates the increased accuracy of the molecular approach. Using the maternally derived cases and probing at 19 polymorphic sites on chromosome 21, we created a genetic map that spans most of the long arm of chromosome 21. The map was significantly shorter than the normal female linkage map, indicating that absence of pairing and/or recombination contributes to nondisjunction in a substantial proportion of cases of trisomy 21.
 ...
PMID:Trisomy 21: association between reduced recombination and nondisjunction. 153

The von Recklinghausen neurofibromatosis (NF1) gene has been mapped to the pericentromeric region of chromosome 17 and various DNA markers have been identified in this region. We have performed a genetic analysis using an anonymous DNA marker, HHH202 (D17S33), tightly linked to the NF1 gene in seven NF1 Italian families. Only one family was fully informative for the HHH202/RsaI polymorphism. In this family this marker can be used for presymptomatic and prenatal diagnosis. However, it is necessary to use additional flanking markers in order to increase informativeness and to obtain better diagnostic accuracy.
 ...
PMID:Molecular study in von Recklinghausen neurofibromatosis (NF1). 190 26

Alpha satellite DNA is composed of variants of a short consensus sequence that are repeated in tandem arrays in the centromeric heterochromatin of each human chromosome. To define centromeric markers for linkage studies, we screened human genomic DNA for restriction fragment length polymorphisms using a probe detecting alphoid sequences on chromosomes 13 and 21. We describe one such DNA polymorphism. Analysis of linkage of this DNA marker to other polymorphic markers in the CEPH pedigrees demonstrates linkage to markers on the proximal long arm of chromosome 13 and defines the centromeric end of the linkage map of this chromosome.
 ...
PMID:An alpha satellite DNA polymorphism specific for the centromeric region of chromosome 13. 197 Jul 94

We have cloned and mapped a 90-kb region spanning the human genomic amiloride-sensitive Na+/H+ antiporter gene on overlapping cosmid clones. This cloned region extends 27 kb upstream of the 5' end of the longest antiporter cDNA and reveals a primary transcription unit of at least 60 kb. Using these genomic clones we have identified polymorphisms in the antiporter gene in human genomic DNA cleaved with enzymes TaqI and MspI; both are two-allele systems. We have localized both polymorphisms to the same segment within an intron of the antiporter transcription unit. Observed heterozygosity for both markers is 47% in 175 unrelated individuals, with the two polymorphic systems showing complete linkage disequilibrium. We have determined genotypes at the antiporter locus in 667 individuals in 59 reference families. Linkage analysis using 28 other markers on human chromosome 1 precisely locates the antiporter gene (locus APNH) on the genetic map of 1 p. The antiporter gene is closely flanked by two highly informative loci, lying 3 cM proximal to the rhesus blood group locus (Rh) and 4 cM distal to the anonymous DNA marker CMM8 (locus D1S79). These antiporter polymorphisms and informative flanking markers will prove useful in genetic linkage studies employing the antiporter gene.
 ...
PMID:Cloning of the human genomic amiloride-sensitive Na+/H+ antiporter gene, identification of genetic polymorphisms, and localization on the genetic map of chromosome 1p. 197 Jul 96

The genetic basis of various subtypes of the affective disorders has been investigated by family, twin, and adoption studies, as well as by segregation and linkage analysis. Linkage analyses of bipolar disorder with the chromosome 11p15 DNA markers HRAS1 and INS, and the chromosome Xq28 markers for color blindness and G6PD have been reported. We have used restriction fragment length polymorphisms as markers to examine linkage in three extended families with unipolar affective illness, ascertained through probands with either recurrent unipolar or bipolar II illness. Using an inclusive definition of the affected phenotype, linkage could be excluded up to 28cM around the HRAS1-INS linkage group on chromosome 11p15, and up to 5 cM around the DNA marker DXS52 on Xq28. Negative linkage results were also obtained for two more restrictive definitions of affective illness. Thus, we find no evidence for the involvement of the chromosomal regions 11p15 and Xq28 with unipolar affective disorder in these three families.
 ...
PMID:Evidence against close linkage of unipolar affective illness to human chromosome 11p markers HRAS1 and INS and chromosome Xq marker DXS52. 197 4

The most common X-linked recessive form of chronic granulomatous disease (X-CGD) is characterized by the absence of cytochrome b558 in neutrophils. In a rare variant form of X-CGD, cytochrome b558 is present but not functional. The gene (locus symbol CYBB) was localized to band Xp21 by studies of patients with small chromosome deletions. The gene was cloned based on its location and found to encode the 91-Kd subunit of the cytochrome b558 complex. Most female carriers for X-CGD can be identified by their X-inactivation mosaicism; on average 50% of their neutrophils express the mutant phenotype and fail to reduce nitroblue tetrazolium (NBT). In 2 of 4 families studied, the maternal grandmothers had normal NBT tests, suggesting either nonrandom X-inactivation or new mutations. Restriction fragment length polymorphism analysis using closely linked flanking markers or the NsiI polymorphism detected by the CYBB probe itself, allowed us to identify the X chromosome carrying the mutation as derived from a healthy NBT-positive maternal grandfather. The mothers of the affected boys must have received a paternal X chromosome carrying a new mutation, consistent with the maternal grandmothers' normal NBT tests. In all of eight potential carriers studied, the results of the NBT and DNA marker testing were in complete agreement. Prenatal diagnosis by DNA testing can be performed in early gestation obviating the need for fetal blood sampling.
 ...
PMID:Origin of mutations in two families with X-linked chronic granulomatous disease. 197 55

Advances in molecular genetics have led to the development of clinical assays for several genetic diseases. Two general testing approaches are available: direct detection of the genetic mutation or indirect detection using DNA markers close to, or within, the defective gene. Direct testing at the nucleic acid level is available for diseases in which the basic defect is well characterized, such as sickle cell anemia. Several methods are available for detection of the point mutation that causes sickle cell anemia including: routine Southern blot analysis, allele specific oligonucleotides, and polymerase chain reaction gene amplification. For diseases such as cystic fibrosis, in which the basic genetic defect has not yet been characterized, an indirect approach is used. This approach relies on linkage analysis using DNA markers close to the genetic defect. Inheritance of the DNA marker is followed through the family. Unlike direct testing, the DNA marker does not detect the actual genetic defect. Therefore, a prediction of inheritance of the linked disease is given based on the risk of recombination between the disease locus and the DNA marker. An appreciation of the differences between the direct and indirect approaches is necessary to understand their attributes and their limitations.
 ...
PMID:Use of nucleic acid probes in genetic tests. 197 33

There are three types of X-linked cataracts recorded in Mendelian Inheritance in Man (McKusick 1988): congenital total, with posterior sutural opacities in heterozygotes; congenital, with microcornea or slight microphthalmia; and the cataract-dental syndrome or Nance-Horan (NH) syndrome. To identify a DNA marker close to the gene responsible for the NH syndrome, linkage analysis on 36 members in a three-generation pedigree including seven affected males and nine carrier females was performed using 31 DNA markers. A LOD score of 1.662 at theta = 0.16 was obtained with probe 782 from locus DXS85 on Xp22.2-p22.3. Negative LOD scores were found at six loci on the short arm, one distal to DXS85, five proximal, and six probes spanning the long arm were highly negative. These results make the assignment of the locus for NH to the distal end of the short arm of the X chromosome likely.
 ...
PMID:Assignment of the Nance-Horan syndrome to the distal short arm of the X chromosome. 197 6

The etiology of non-insulin-dependent diabetes mellitus (NIDDM) is still unclear, but appears to involve some genetic factors. There have been disputes over the association between DNA sequences flanking the insulin gene and NIDDM. In order to characterize insulin gene polymorphism in the Chinese population and elucidate its association with NIDDM, 100 unrelated Chinese subjects living in Taiwan were observed for polymorphism of this hypervariable region. Most of them were descendants of immigrants from the southern part of mainland China. Among them, 52 were nondiabetic controls, and 48 were subjects with NIDDM. Insulin gene polymorphism was classified into classes 1, 2 and 3 alleles according to Bell et al. Neither the class 2 allele nor the genotype for the homozygous class 3 allele was not observed in this study. The allelic frequencies of class 1 and 3 genes were 97% and 3% in the nondiabetic subjects, and 99% and 1% in the NIDDM group, respectively. The frequencies of genotypes 1/1 and 1/3 were 94% and 6% in nondiabetics and 98% and 2% in the NIDDM group, respectively. No significant association was found between insulin gene polymorphism and NIDDM. It is concluded that DNA marker flanking the insulin gene may not be associated with the development of NIDDM in Chinese subjects.
 ...
PMID:Polymorphic locus in the 5'-flanking region of human insulin gene and non-insulin-dependent diabetes mellitus. 198 27


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>